Protesters upset over severe electricity shortages have clashed with police for a second day in eastern Pakistan’s Gujranwala city.

Local television footage showed demonstrators on Tuesday throwing stones at police dressed in full riot gear. The police threw some of the rocks back, charged the protesters with their batons raised and lobbed tear gas into the crowds.

Gujranwala police chief Ahsan Tufail said mobs burned six electricity company offices Monday and set fire to several rooms in a police station. Fourteen policemen were injured in clashes Monday and 20 people were arrested.

Pakistan has been plagued by power shortages of up to 18 hours per day in some parts of the country. The shortages have severely affected businesses across Pakistan.